Xcelerator
Xcelerator is a steel launched roller coaster at Knott's Berry Farm in Buena Park, California. It was Intamin's first hydraulically launched coaster, while also the fourth Intamin installation at Knott's, alongside The Sky Cabin, Bigfoot Rapids, and Perilous Plunge (removed in 2012). Xcelerator was standing but not operating from July 2017 but the coaster finally reopened on March 24, 2018. Ride experience Xcelerator's powerful hydraulic catapult motor accelerates the train from 0 to 82 mph (132 km/h) in 2.3 seconds (about 1.62 g). It only uses 157 feet (48 m) of track to launch the train. The twin hydraulic catapult motor achieves a maximum of 10,500 horsepower (7,800 kW) each while accelerating the train. Xcelerator's hydraulic motor system has the mechanical capability of accelerating vehicles to a speed of 117 miles per hour (188 km/h) or more, though it only needs to hit 82 mph (132 km/h) for the train to crest the hill. In order for a train to launch, the train must "drift" back to "hook" on to a catch car. Twenty-four volts are used to demagnetize a pin underneath the third car, which causes it to drop. At the same time, two bellows actuators fill up with air. Meanwhile, near the back of the train, two drive tires that are holding the train in place begin to retract. The brakes will lower while the train rolls back to hook into the catch car—which is over 7 feet (2.1 m) long. Once connected the motor will engage to launch the train. The catch car passes over its own set of magnetic brakes to retard it. The motor has to work harder to attain launch speed if the train is not loaded with enough riders. On occasion, the catch car can overshoot its end position if it cannot attain the proper speed within set parameters, which causes it to stall near the end of the launch track. The train must also clear the launch track within three seconds. If it does not the ride will shut down. From the time the launch begins, the train has 8.25 seconds to pass over a proximity switch (Hall effect sensor) near the bottom of the first drop which clears the starting block. If the train does not pass over the switch within the given time frame, the ride will shut itself down. After the launch the train crests a vertical 205 ft (62 m) top hat element, then soars through a 110 ft (34 m) and 95 ft (29 m) over banked turns, and glides to a smooth stop though brake run and returns to the station house. The magnetic braking system consists of mounted magnetic clippers on the trains and copper alloy fins mounted onto the track. The alloy fins on the launch section retract during the launch procedure so as to not interfere with the train. In a case of a rollback, the magnetic brakes retard the train. They are raised section by section after the train has passed over them. The brake fins on the brake run are stationary and cannot be lowered. The train is traveling at approximately 67 miles per hour (108 km/h) when entering the brake run.